Ocean's 17 trillion pieces of plastic debris may persist for centuries
A new study reveals that there are 17 trillion pieces of plastic debris floating in the world's oceans. Researchers warn that this persistent plastic pollution could disrupt ecosystems and the crucial role of the ocean in regulating the climate.
The study conducted by researchers at Queen Mary University of London indicates that even if all new pollution were to stop immediately, plastic pollution in the ocean might take more than a century to disappear.
Most of the large floating plastics slowly degrade on the surface over decades, breaking down into smaller particles, but about 94% of the plastic eventually sinks to the seabed and remains there for centuries.
The study results confirm that plastic pollution is a generational issue, requiring mitigation strategies such as limiting plastic production and improving comprehensive tracking of its sources.
Plastic poses great harm to human and animal health, with tiny particles known as microplastics and nanoplastics found in arteries, brains, hearts, and reproductive organs. Although doctors are still studying their effects, these particles have been linked to cancer, diabetes, heart disease, and changes in gut health.
Dr. Nan Wu, a researcher at the university, said, "People often assume that plastic in the ocean sinks to the seabed or simply disappears. But our model shows that most large floating plastic degrades slowly on the surface, breaking down into smaller particles over decades."
These small fragments may combine with "marine snow" and eventually reach the seabed, but this process takes time. Even after 100 years, about 10% of the original plastic may still remain on the surface.
Dr. Kim Warner, chief scientist at the ocean conservation organization Oceana, pointed out, "This situation could last for decades unless something can break down plastic in the extremely cold environments of the ocean during this period."
Although plastic on the surface breaks down under sunlight or wave action, plastic sinking to the seabed decomposes more slowly, thus affecting the ocean's ability to absorb heat and carbon dioxide and produce oxygen.
According to the National Oceanic and Atmospheric Administration (NOAA), some types of plastic contain chemicals that make them more resistant to these forces.
Researchers say their findings indicate that plastic pollution may increase the burden on the ocean's natural "conveyor belt," a crucial movement caused by deep and surface currents responsible for transporting heat and nutrients around the globe.
According to this study, the United States is one of the major contributors to global plastic pollution, producing 507 million tons of plastic annually. According to a report by the ocean conservation organization Ocean Conservancy, over 11 million tons of plastic pollutants enter the ocean each year.
Plastic pollution extends far beyond the ocean, existing in rivers, streams, lakes, and land, and even spreading microscopic particles in the air we breathe.
Professor Kate Spencer, who participated in the study, said that the researchers' findings confirm the long-term nature of the human-caused problem and that it has become an extremely dangerous global crisis.
She added, "This tells us that microplastic pollution is a generational issue. Even if we stop plastic pollution tomorrow, our descendants will still be struggling to clean up our oceans."
Approximately 450 million tons of plastic are produced globally each year, half of which is single-use. Of the plastic waste, 15% is collected for recycling, and only about 10% of that is actually recycled.
About 46% of the plastic ends up in landfills, 17% is incinerated, and 22% is poorly managed, becoming waste that severely pollutes the air, soil, and ocean, causing widespread pollution.
Sources: Al Jazeera Plus Press Agency
Original: www.toutiao.com/article/1847185092600832/
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